Difficulty in rising from a bed or chair is a common problem in older persons, is associated with adverse outcomes, and is an important part of performance-oriented geriatric assessment. Previous research both by our group and others suggests that maintenance of balance, particularly in the trunk, may be as important as extremity muscle strength and joint range of motion in performing these activities of daily living. Our previous work provides us with unique insights into the key components of rising from a bed and from a chair. To our knowledge, using these components in a quantitative, empirical training program to improve bed and chair rise mobility has not been explored. We will thus attempt to improve the bed and chair rise ability of older adults aged 65 and over who complain of at least some difficulty in rising from a bed or chair. This training program focuses on bed and chair mobility, i.e. it is task-specific, and it is designed to progressively increase the resistance to performing certain bed and chair mobility tasks, such as by the addition of a weighted vest. A 12 week controlled intervention will be conducted, such that an initial Training group receives the task specific exercise and a Control group receives flexibility exercises. Following this 12 week intervention trial, Controls then also receive the task-specific training intervention. Subjects will be tested for balance, musculoskeletal, and behavioral function, as well as in bed and chair rise performance at regular intervals. A period of testing for detraining effects will follow, for a total of 42 weeks of maximum involvement for a subject in the project. We propose that improvement (and decline) in chair and bed rise performance can be predicted by changes in trunk strength and balance, and by changes in behavioral function, such as in improved (and decreased) self efficacy in performing daily tasks. The proposed program is expected to improve the bed and chair rise performance of participating subjects. In addition, results from this study can: 1) be used to quantify improvement in function as a result of ongoing traditional therapy programs; 2) serve as adjuncts or refinements for present therapy programs, particularly in identifying critical components of training; and 3) impact upon design specifications of living environments for older adults, especially for those who are mobility- impaired and/or undergoing rehabilitation.